Mixed progress in adolescent health and wellbeing in Aotearoa New Zealand 2001–2019: a population overview from the Youth2000 survey series

Figures & data

Table 1. Demographic characteristics of Youth2000 participants across survey waves (2001, 2007, 2012 and 2019)

	2001		2007		2012		2019
	N	%	N	%	N	%	N	%
Total schools	114	–	96	–	91	–	45	–
Total students	9,546	100.0	9,098	100.0	8,487	100.0	7,311	100.0
Sex ^a
Female	5,144	53.9	4,187	46.0	4,618	54.4	3,990	54.6
Male	4,402	46.1	4,911	54.0	3,869	45.6	3,321	45.4
Age ^b
13 years or under	2,050	21.5	1,859	20.4	1,838	21.7	1,323	18.1
14	2,285	23.9	2,100	23.1	1,895	22.3	1,635	22.4
15	2,178	22.8	1,973	21.7	1,755	20.7	1,620	22.2
16	1,725	18.1	1,743	19.2	1,578	18.6	1,403	19.2
17 years or over	1,308	13.7	1,423	15.6	1,421	16.7	1,330	18.2
Ethnicity ^c
Māori	2,335	24.5	1,702	18.7	1,697	20.0	1,188	16.2
Pacific	765	8.0	924	10.2	1,200	14.1	915	12.5
Asian	679	7.1	1,126	12.4	1,049	12.4	1,768	24.2
Other ^d	365	3.8	549	6.0	523	6.2	387	5.3
Pākehā & European	5,402	56.6	4,797	52.7	4,018	47.3	3,053	41.8
Neighbourhood deprivation ^e,f
NZDep 1–3 (low deprivation)	–	–	3,216	35.3	2,715	32.0	2,098	28.7
NZDep 4–7	–	–	3,396	37.3	2,995	35.3	2,772	37.9
NZDep 8–10 (high deprivation)	–	–	2,246	24.7	2,670	31.5	1,829	25.0
School decile ^g
Decile 1–2 (high deprivation)	957	10.0	629	6.9	1,222	14.4	734	10.0
Decile 3–4	1,491	15.6	1,751	19.2	1,411	16.6	1,189	16.3
Decile 5–6	2,361	24.7	2,458	27.0	1,728	20.4	893	12.2
Decile 7–8	2,464	25.8	1,347	14.8	2,254	26.6	1,740	23.8
Decile 9–10 (low deprivation)	2,273	23.8	2,913	32.0	1,872	22.1	2,755	37.7
Urban / rural ^f,h
Urban	–	–	6,688	73.5	6,591	77.7	5,085	69.6
Small towns	–	–	726	8.0	517	6.1	520	7.1
Rural	–	–	1,390	15.3	1,216	14.3	1,095	15.0

NB some percentages do not add to 100 due to missing data.

^a 2019 was the first survey in which students were able to report a sex other than male or female. A total of 63 students did not report a male or female sex in 2019. Their health and wellbeing will be reported in other outputs where contexts can be explored more fully.

^b Very few participants were younger than 13 or older than 17, therefore these students were grouped into ’13 or under’ or ’17 or over’.

^c Ethnicity is categorised using the NZ census ethnicity prioritisation method.

^d ‘Other’ ethnicity includes Middle Eastern, Latin American, African, and other ethnicities and ethnicity unknown.

^e Neighbourhood deprivation is categorised using the NZ Deprivation Index 2018.

^f Home addresses allowing the attribution of meshblock and location data were not collected in 2001.

^g School decile is determined by the Ministry of Education and indicates the extent to which a school draws students from low socio-economic communities.

^h Urban (population of 10,000 or more), small towns (population between 1,000 and 9,999 people), rural (population fewer than 1,000), based on the Statistical Standard for Geographic Areas 2018 (SSGA18), see Fleming et al. (2020b) for full details.

Table 2. Selected risk and protective factors and social context variables by sex and associations between variables and survey wave (2001, 2012 and 2019)

	2001 (except where specified)		2012		2019		Changes from 2001^b to 2019			Changes from 2012 to 2019
	n	% (95% CI)	n	% (95% CI)	n	% (95% CI)	OR (95% CI)	Δ	p value	OR (95% CI)	Δ	p value
Family circumstances
Moved home two or more times in past year Total Female Male	1,029 612 417	10.0 (9.3-10.7) 11.0 (9.9-12.2) 9.1 (8.1-10.0)	622 342 280	6.9 (6.3-7.5) 6.8 (6.0-7.5) 7.0 (6.1-8.0)	526 313 213	7.7 (6.8-8.6) 7.8 (6.7-9.0) 7.5 (6.3-8.7)	0.75 (0.64-0.86) 0.69 (0.57-0.84) 0.82 (0.66-1.01)	↓ ↓ -	<.001 <.001 .060	1.12 (0.96-1.31) 1.17 (0.96-1.43) 1.08 (0.86-1.35)	- - -	.141 .118 .531
Parent often or always worry about not having enough money for food Total Female Male	663 394 269	7.2 (6.7-7.8) 7.7 (6.7-8.6) 6.8 (5.8-7.7)	918 522 396	10.1 (9.3-10.9) 10.5 (9.3-11.8) 9.7 (8.4-11.1)	896 524 372	12.5 (11.4-13.7) 12.4 (10.3-14.4) 12.7 (10.4-15.0)	1.85 (1.61-2.11) 1.70 (1.35-2.14) 2.01 (1.55-2.61)	↑ ↑ ↑	<.001 <.001 <.001	1.27 (1.11-1.46) 1.20 (0.95-1.51) 1.35 (1.04-1.75)	↑ - ↑	<.001 .124 .025
Always feels safe in neighbourhood ^a Total Female Male	3,768 1,775 1,993	43.8 (41.9-45.7) 36.8 (34.7-38.9) 51.0 (48.5-53.5)	4,285 2,323 1,962	55.2 (53.6-56.7) 53.5 (51.7-55.4) 56.8 (54.6-59.0)	4,007 2,028 1.979	58.8 (57.2-60.4) 53.2 (51.2-55.2) 64.7 (62.3-67.1)	1.84 (1.66-2.03) 1.96 (1.73-2.21) 1.76 (1.52-2.03)	↑ ↑ ↑	<.001 <.001 <.001	1.16 (1.06-1.27) 0.99 (0.88-1.10) 1.39 (1.21-1.60)	↑ - ↑	.001 .817 <.001
Family connectedness
Feel at least one parent cares for them a lot Total Female Male	8,652 4,674 3,978	93.0 (92.5-93.6) 93.0 (92.3-93.8) 93.0 (92.1-93.9)	7,764 4,249 3,515	93.4 (92.9-93.9) 93.6 (92.9-94.4) 93.2 (92.4-93.9)	5,893 3,558 2,335	93.2 (92.6-93.9) 93.3 (92.5-94.0) 93.2 (91.9-94.5)	1.04 (0.90-1.18) 1.04 (0.88-1.23) 1.03 (0.80-1.32)	- - -	.617 .642 .821	0.97 (0.85-1.12) 0.94 (0.79-1.12) 1.00 (0.79-1.27)	- - -	.702 .509 .970
Family usually or always wants to know who you are with and where you are Total Female Male	7,863 4,441 3,422	83.6 (82.8-84.4) 87.8 (86.6-89.0) 79.3 (78.0-80.7)	7,709 4,312 3,397	90.6 (89.9-91.2) 93.5 (92.7-94.3) 87.7 (86.7-88.7)	6,681 3,735 2,946	91.2 (89.8-92.5) 93.7 (92.4-95.0) 88.6 (87.0-90.2)	2.03 (1.70-2.42) 2.07 (1.62-2.64) 2.03 (1.70-2.43)	↑ ↑ ↑	<.001 <.001 <.001	1.08 (0.90-1.29) 1.04 (0.81-1.34) 1.09 (0.91-1.32)	- - -	.424 .756 .349
School
Feels part of school Total Female Male	7,602 4,086 3,516	82.2 (81.2-83.1) 81.7 (80.5-82.9) 82.6 (81.2-84.1)	7,390 4,017 3,373	86.7 (85.9-87.5) 86.5 (85.3-87.8) 86.9 (85.9-87.9)	6,165 3,442 2,723	85.0 (84.0-85.9) 88.3 (86.9-89.7) 81.6 (80.0-83.3)	1.23 (1.11-1.35) 1.69 (1.44-1.97) 0.94 (0.81-1.08)	↑ ↑ -	<.001 <.001 .371	0.87 (0.78-0.96) 1.17 (0.99-1.39) 0.67 (0.58-0.77)	↓ - ↓	.006 .070 <.001
Feels safe at school all or most of the time Total Female Male	7,334 4,007 3,327	78.7 (77.4-80.1) 79.8 (77.7-82.0) 77.6 (75.8-79.4)	7,352 4,065 3,287	87.1 (85.7-88.5) 88.7 (86.9-90.5) 85.5 (83.8-87.2)	6,331 3,474 2,857	87.0 (85.2-88.9) 88.6 (86.8-90.4) 85.5 (82.6-88.3)	1.82 (1.52-2.17) 1.97 (1.58-2.46) 1.69 (1.32-2.18)	↑ ↑ ↑	<.001 <.001 <.001	1.00 (0.81-1.22) 1.00 (0.77-1.28) 1.00 (0.76-1.30)	- - -	.978 .969 .975
Health Care
Accessed health care in the past 12 months ^b Total Female Male	7,299 3,444 3,855	(2007 data) 83.5 (82.6-84.4) 84.9 (83.7-86.2) 82.1 (80.9-83.2)	6,608 3,706 2,902	80.5 (79.5-81.4) 83.3 (81.7-84.8) 77.8 (76.3-79.2)	5,493 3,037 2,456	78.2 (77.1-79.3) 80.0 (78.6-81.0) 76.7 (75.0-78.4)	0.71 (0.65-0.78) 0.70 (0.62-0.79) 0.72 (0.64-0.81)	↓ ↓ ↓	<.001 <.001 <.001	0.87 (0.80-0.95) 0.79 (0.70-0.91) 0.94 (0.83-1.07)	↓ ↓ -	.003 <.001 .352
Forgone health care (unable to access health care when wanted or needed at least once in past 12 months) ^b Total Female Male	1,485 804 681	(2007 data) 16.7 (15.9-17.6) 19.1 (17.7-20.4) 14.4 (13.3-15.5)	1,564 968 596	17.9 (17.1-18.7) 20.8 (19.6-22.0) 15.1 (14.0-16.1)	1,448 845 603	20.1 (18.9-21.4) 21.1 (19.7-22.4) 19.2 (17.5-20.9)	1.26 (1.14-1.38) 1.13 (1.00-1.28) 1.41 (1.23-1.63)	↑ ↑ ↑	<.001 .043 <.001	1.16 (1.05-1.27) 1.02 (0.91-1.13) 1.34 (1.17-1.54)	↑ - ↑	.003 .780 <.001
Violence and Abuse
Bullied at school weekly or more in the past 12 months Total Female Male	656 265 391	7.1 (6.5-7.7) 5.0 (4.3-5.7) 9.3 (8.4-10.1)	525 261 264	6.3 (5.7-6.8) 5.6 (5.0-6.3) 6.9 (6.0-7.8)	383 202 181	5.9 (4.9-6.9) 5.6 (4.6-6.6) 6.1 (4.8-7.5)	0.82 (0.67-1.00) 1.14 (0.89-1.45) 0.64 (0.49-0.83)	- - ↓	.051 .300 <.001	0.93 (0.76-1.15) 1.00 (0.80-1.25) 0.88 (0.67-1.17)	- - -	.515 .984 .382
Witnessed an adult at home hit or physically hurt another adult in past 12 months ^b Total Female Male	901 455 446	(2007 data) 9.9 (9.3-10.6) 10.7 (9.6-11.8) 9.2 (8.2-10.1)	607 342 265	6.8 (6.2-7.3) 6.6 (5.7-7.5) 6.9 (6.1-7.7)	405 257 148	6.1 (5.6-6.6) 6.7 (5.9-7.4) 5.5 (4.5-6.5)	0.59 (0.52-0.66) 0.60 (0.51-0.70) 0.58 (0.46-0.72)	↓ ↓ ↓	<.001 <.001 <.001	0.90 (0.79-1.02) 1.01 (0.84-1.22) 0.78 (0.63-0.98)	- - ↓	.087 .922 .033
Ever experienced sexual violence, abuse or unwanted sexual behaviour ^c Total Female Male	2,080 1,395 685	22.6 (21.7-23.5) 28.9 (27.5-30.4) 16.2 (14.9-17.5)	1,386 980 406	15.9 (14.9-16.9) 21.5 (20.2-22.8) 10.3 (9.0-11.6)	1,196 904 292	18.0 (17.0-19.1) 26.1 (23.9-28.2) 9.7 (8.7-10.7)	0.75 (0.69-0.82) 0.87 (0.76-0.99) 0.56 (0.48-0.65)	↓ ↓ ↓	<.001 .034 <.001	1.16 (1.05-1.29) 1.29 (1.12-1.47) 0.94 (0.78-1.12)	↑ ↑ -	.004 <.001 .476

The numbers reported (n) are based on the raw number of responses. The reported percentages, odds ratios (OR) and 95% confidence intervals (CI) are national prevalence estimates (i.e. the data has been calibrated to adjust for differences between the national population of students and those who took part in the surveys). Arrows indicate a statistically significant difference.

NA – Not applicable because there was not a comparable question and/or response options to 2019 for the wave(s) that ORs have not been reported.

^a Response options in 2001 and 2007 were ‘yes, all the time’ / ‘yes, most of the time’ / ‘sometimes’ / ‘no, mostly not’ / ‘not at all’. In 2012 and 2019, options were ‘all the time’ / ‘sometimes’ / ‘not often’ / ‘never’.

^b 2019 has been compared to 2007 instead of 2001 (and the 2007 data has been reported) because the question was not asked in 2001 or was not comparable.

^c Students responded ‘yes’ or ‘maybe / not sure’. In 2007 and 2012 there was also an ‘I don’t want to answer’ response option.

Table 3. Selected health and wellbeing variables by sex and associations between variables and survey wave (2001, 2012 and 2019)

	2001 (except where specified)		2012		2019		Changes from 2001^a to 2019			Changes from 2012 to 2019
	n	% (95% CI)	n	% (95% CI)	n	% (95% CI)	OR (95% CI)	Δ	p value	OR (95% CI)	Δ	p value
General health
General health (good, very good or excellent) Total Female Male	8,683 4,595 4,088	92.2 (91.7-92.8) 90.4 (89.5-91.2) 94.1 (93.4-94.8)	7,699 4,088 3,611	91.5 (90.8-92.3) 88.9 (87.8-90.1) 94.1 (93.3-94.9)	6,569 3,511 3,058	91.0 (90.1-91.8) 89.0 (88.0-90.1) 92.9 (91.7-94.0)	0.84 (0.74-0.97) 0.87 (0.75-1.00) 0.81 (0.66-1.00)	↓ ↓ -	.014 .049 .057	0.93 (0.80-1.08) 1.01 (0.87-1.18) 0.82 (0.66-1.02)	- - -	.328 .882 .077
Emotional and mental health
Good psychological wellbeing (WHO-5 ≥ 13) over past 2 weeks ^a Total Female Male	6,804 2,887 3,917	(2007 data) 78.2 (77.4-79.0) 72.2 (70.9-73.4) 84.3 (83.1-85.4)	6,306 3,233 3,073	76.0 (75.0-77.0) 70.0 (68.3-71.6) 82.0 (81.1-83.0)	4,835 2,331 2,504	69.1 (67.6-70.6) 60.1 (58.4-61.8) 78.1 (76.2-80.0)	0.62 (0.57-0.68) 0.58 (0.53-0.64) 0.67 (0.58-0.77)	↓ ↓ ↓	<.001 <.001 <.001	0.70 (0.64-0.77) 0.65 (0.58-0.72) 0.78 (0.69-0.89)	↓ ↓ ↓	<.001 <.001 <.001
Significant depressive symptoms (RADS-SF) Total Female Male	1,154 782 372	11.8 (11.1-12.5) 14.7 (13.5-15.8) 8.8 (8.0-9.7)	1,078 763 315	13.0 (12.2-13.9) 17.4 (16.1-18.6) 8.7 (7.6-9.8)	1,727 1,218 509	22.8 (21.4-24.1) 29.0 (27.2-30.9) 16.4 (14.9-17.9)	2.21 (2.00-2.44) 2.38 (2.09-2.71) 2.03 (1.74-2.37)	↑ ↑ ↑	<.001 <.001 <.001	1.96 (1.76-2.19) 1.94 (1.72-2.20) 2.06 (1.72-2.46)	↑ ↑ ↑	<.001 <.001 <.001
Seriously thought about committing suicide in the past 12 months ^a Total Female Male	1,231 795 436	(2007 data) 14.5 (13.7-15.2) 19.4 (18.2-20.6) 9.5(8.6-10.4)	1,307 937 370	15.3 (14.5-16.2) 20.8 (19.2-22.3) 10.0 (9.0-11.0)	1,501 1,002 499	20.8 (19.2-22.4) 24.6 (22.8-26.4) 16.9 (14.8-19.1)	1.55 (1.39-1.74) 1.35 (1.20-1.53) 1.94 (1.62-2.34)	↑ ↑ ↑	<.001 <.001 <.001	1.45 (1.29-1.63) 1.24 (1.09-1.42) 1.84 (1.53-2.22)	↑ ↑ ↑	<.001 .002 <.001
Suicide attempt in past 12 months ^b Total Female Male	739 536 203	7.1 (6.5-7.7) 9.6 (8.4-10.7) 4.6 (3.9-5.3)	377 284 93	3.9 (3.4-4.3) 5.5 (4.8-6.3) 2.2 (1.7-2.8)	439 310 129	6.3 (5.5-7.0) 7.4 (6.2-8.6) 5.1 (3.7-6.5)	0.88 (0.75-1.03) 0.76 (0.61-0.94) 1.12 (0.81-1.55)	- ↓ -	.104 .012 .507	1.67 (1.40-1.99) 1.37 (1.10-1.71) 2.36 (1.60-3.49)	↑ ↑ ↑	<.001 .006 <.001
Sexual health
Ever had consensual sexual intercourse ^c Total Female Male	2,847 1,505 1,342	31.6 (30.5-32.8) 30.7 (29.0-32.4) 32.6 (30.7-34.5)	1,990 1,080 910	25.8 (24.7-26.9) 26.1 (24.7-27.5) 25.5 (23.5-27.5)	1,180 577 603	20.6 (19.6-21.7) 17.9 (16.8-19.0) 23.5 (21.7-25.2)	0.56 (0.52-0.61) 0.49 (0.44-0.55) 0.63 (0.56-0.72)	↓ ↓ ↓	<.001 <.001 <.001	0.75 (0.68-0.82) 0.62 (0.56-0.69) 0.90 (0.78-1.03)	↓ ↓ -	<.001 <.001 .131
Always use contraception to prevent pregnancy ^d Total Female Male	1,099 613 486	61.4 (59.2-63.6) 60.5 (57.3-63.7) 62.5 (59.2-65.8)	870 511 359	59.5 (56.9-62.2) 62.2 (58.6-65.8) 56.5 (52.5-60.4)	366 222 144	56.2 (52.5-59.9) 60.2 (55.7-64.8) 52.3 (46.1-58.6)	0.81 (0.68-0.96) 0.99 (0.79-1.25) 0.66 (0.49-0.88)	↓ - ↓	.017 .931 .005	0.87 (0.73-1.05) 0.92 (0.72-1.17) 0.85 (0.63-1.14)	- - -	.153 .509 .274
Always use condoms to protect against STIs ^d,e Total Female Male	898 445 453	48.3 (46.0-50.5) 42.0 (38.9-45.0) 55.3 (52.3-58.4)	683 346 337	45.9 (43.5-48.2) 40.1 (36.5-43.6) 52.5 (49.1-55.8)	249 129 120	36.8 (32.5-41.2) 32.5 (28.5-36.6) 40.9 (33.5-48.4)	0.63 (0.51-0.77) 0.67 (0.53-0.83) 0.56 (0.40-0.78)	↓ ↓ ↓	<.001 <.001 <.001	0.69 (0.56-0.85) 0.72 (0.57-0.91) 0.63 (0.45-0.88)	↓ ↓ ↓	<.001 .007 .007
Physical Activity
Vigorous physical activity 7+ times in the past week ^a Total Female Male	1,619 458 1,161	(2007 data) 18.2 (17.0-19.3) 11.2 (10.0-12.4) 25.1 (23.5-26.7)	1,537 588 949	18.6 (17.8-19.5) 12.2 (11.1-13.4) 25.0 (23.7-26.2)	1,065 420 645	16.6 (15.8-17.3) 11.8 (10.9-12.7) 21.4 (20.3-22.6)	0.90 (0.81-0.98) 1.06 (0.91-1.23) 0.82 (0.73-0.91)	↓ - ↓	.023 .455 <.001	0.87 (0.80-0.94) 0.96 (0.84-1.10) 0.82 (0.74-0.90)	↓ - ↓	<.001 .565 <.001
Substance Use
Cigarette use monthly or more often Total Female Male	1,597 1,002 595	17.5 (16.4-18.7) 19.9 (18.3-21.4) 15.1 (13.6-16.7)	474 260 214	5.9 (5.2-6.5) 5.6 (4.6-6.6) 6.2 (5.3-7.0)	262 155 107	4.7 (4.1-5.2) 5.0 (4.2-5.8) 4.3 (3.4-5.2)	0.23 (0.20-0.27) 0.21 (0.17-0.26) 0.25 (0.20-0.32)	↓ ↓ ↓	<.001 <.001 <.001	0.78 (0.66-0.93) 0.88 (0.68-1.14) 0.69 (0.53-0.89)	↓ - ↓	.005 .336 .004
Used marijuana at least once in the past 4 weeks Total Female Male	1,641 865 776	19.1 (18.0-20.2) 18.0 (16.5-19.5) 20.3 (18.3-22.2)	672 303 369	9.4 (8.4-10.5) 7.8 (6.6-9.0) 11.1 (9.7-12.4)	562 276 286	9.9 (8.8-10.9) 9.5 (8.0-10.9) 10.3 (8.7-11.8)	0.46 (0.40-0.53) 0.48 (0.39-0.58) 0.45 (0.37-0.56)	↓ ↓ ↓	<.001 <.001 <.001	1.05 (0.89-1.25) 1.24 (0.98-1.56) 0.92 (0.74-1.15)	- - -	.559 .076 .466
Binge drinking at least once in the past 4 weeks ^f Total Female Male	3,451 1,829 1,622	41.5 (39.9-43.0) 40.0 (38.2-41.7) 43.0 (40.8-45.2)	1,840 995 845	25.3 (23.8-26.8) 24.9 (23.3-26.4) 25.7 (23.1-28.4)	1,221 642 579	21.8 (20.1-23.4) 20.7 (18.9-22.6) 22.8 (19.9-25.7)	0.39 (0.35-0.44) 0.39 (0.34-0.45) 0.39 (0.32-0.47)	↓ ↓ ↓	<.001 <.001 <.001	0.82 (0.72-0.93) 0.79 (0.69-0.91) 0.85 (0.69-1.06)	↓ ↓ -	.002 .001 .148
Motor vehicle risk behaviours
Always wear a seatbelt when in a car Total Female Male	6,176 3,353 2,823	67.3 (65.9-68.7) 67.8 (66.1-69.5) 66.8 (64.6-69.0)	6,238 3,412 2,826	74.9 (73.6-76.3) 75.6 (73.7-77.6) 74.2 (72.5-75.9)	5,231 2,889 2,342	75.7 (74.0-77.3) 77.3 (75.3-79.3) 74.0 (71.5-76.5)	1.51 (1.36-1.68) 1.62 (1.41-1.86) 1.41 (1.20-1.66)	↑ ↑ ↑	<.001 <.001 <.001	1.04 (0.93-1.17) 1.10 (0.94-1.28) 0.99 (0.84-1.16)	- - -	.493 .240 .884
Dangerous/risky/drink driving as passenger or driver in past month ^g Total Female Male	5,462 2,869 2,593	58.8 (57.6-60.0) 57.3 (55.9-58.7) 60.3 (58.4-62.3)	3,002 1,612 1,390	37.1 (35.9-38.4) 36.2 (34.6-37.7) 38.1 (36.0-40.1)	1,825 968 857	34.0 (31.2-36.8) 32.2 (28.9-35.4) 36.0 (32.1-39.8)	0.36 (0.32-0.41) 0.35 (0.30-0.42) 0.37 (0.31-0.45)	↓ ↓ ↓	<.001 <.001 <.001	0.87 (0.76-1.00) 0.84 (0.71-0.99) 0.91 (0.76-1.10)	↓ ↓ -	.0499 .035 .346

The numbers reported (n) are based on the raw number of responses. The reported percentages, odds ratios (OR) and 95% confidence intervals (CI) are national prevalence estimates (i.e. the data has been calibrated to adjust for differences between the national population of students and those who took part in the surveys). NA – Not applicable because there was not a comparable question and/or response options to 2019 in the wave(s) for which ORs have not been reported.

^a 2019 has been compared to 2007 instead of 2001 (and the 2007 data has been reported) because either the question was not asked in 2001 or was not comparable.

^b In 2001, only students who reported they had thought about attempting suicide in the past 12 months were asked if they had made a suicide attempt. Students who responded they had not thought about attempting suicide were coded as 'no' for attempting suicide. In 2007, 2012 and 2019, all students were asked the attempted suicide question.

^c In 2012 and 2019, students were asked whether they had ever had sexual intercourse, not including sexual abuse. In 2001 and 2007, students were asked what age they first had sexual intercourse (and could respond ‘never’), and the question did not explicitly exclude sexual abuse.

^d For contraceptive use and condom use, students who had not had sex in the previous three months or who responded that the question did not apply to them were excluded from the analyses.

^e For condom use, '(or your partner)' was added to the question wording from the 2007 survey wave onwards.

^f Five or more alcoholic drinks in one 4-hour session.

^g In the past month, had either driven dangerously (i.e. speeding, racing, burnouts) or driven when drinking, or had been a passenger in a car driven dangerously or by someone who had been drinking

Fleming T, Peiris-John R, Crengle S, Archer D, Sutcliffe K, Lewycka S, Clark TC. 2020b. Youth19 Rangatahi Smart survey, initial findings: introduction and methods. New Zealand: The Youth19 Research Group, The University of Auckland and Victoria University of Wellington. [accessed 2021 Nov 11]. https://www.youth19.ac.nz/publications/introduction-and-methods-report.

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